Overhead frame structures are typically fabricated of one or more members forming a framework. Such structures can be used on a vehicle for one or more reasons. The structures can be utilized to protect an operator from injury in the event of accidental upset or inadvertent rollover of the vehicle. Additionally, the structures can be used for mounting various accessories thereto. Further, the frameworks of the structures can be used to mount enclosure elements thereto.
Each framework member of an overhead frame structure is composed of one or more portions. If composed of more than one portion, the corresponding member is generally assembled by either connecting such portions together directly or indirectly using one or more interconnecting brackets. Such methods of connecting the member portions are generally facilitated via the use of one or more fasteners. Once each member of the frame structure is provided, the overhead frame structure can in turn be formed by connecting the members together directly or indirectly using one or more interconnecting brackets (if necessary) and connecting the members to the vehicle. Such methods of connecting the members to other members and/or the frame are generally facilitated via the use of one or more fasteners.
While mounting an overhead frame structure on a vehicle may be advantageous for a variety of reasons as exemplified above, certain situations may exist in which one would want to temporarily modify the structure's configuration. For example, the vehicle may be driven in low overhead clearance areas, during which the process of maneuvering the vehicle having the overhead frame structure is made difficult. As a consequence, certain overhead frame structures have been designed to be adjustable. For example, in some designs, an upper part of the structure is made adjustable with respect to a lower part of the structure. In turn, the upper part can be lowered with respect to the lower part to provide a desirable height for the overhead frame structure. In some designs, this adjustment is facilitated by removal of at least one arresting device used to hold the upper and lower parts together, either directly or through the use of an interconnecting bracket. In such designs, the arresting members can involve fasteners using linchpins, which enables quick changeover of the overhead frame structure from one configuration (e.g., with upper parts raised) to another configuration (e.g., with upper parts lowered). Using fasteners with linchpins as the arresting members also typically enables the connected parts or one of the parts and interconnecting bracket(s) to have some freedom in their connection.
Quite often, vehicles accommodating overhead frame structures are operated in regions of rough terrain. As such, the center of gravity of the vehicles can be found to temporarily change as the vehicles travel over such terrain. Consequently, one or more of the members forming the overhead frame structures can be found to shift in position with each change of vehicle center of gravity. In designs where there is freedom in the connection of the members or parts thereof of the overhead frame structure (as exemplified above), this shift of the members can cause these members and/or parts thereof to generally vibrate against other members or interconnecting brackets. This vibration, in turn, can cause a rattling to occur between these bodies. In addition, this vibration can temporarily stress one or more of the fasteners connecting the members or parts and/or the interconnecting brackets. Over time, the stress experienced by the one or more fasteners of the overhead frame structure due to this vibration can be found to weaken the fasteners.
Embodiments of the present invention are directed to overcoming, or at least reducing these limitations.